When calculating their taxable income, firms in most industrial sectors in the United States are generally allowed to deduct a portion of the investment costs they incurred that year and in previous years. The portion of those costs that is deductible depends on prescribed rates of depreciation or, for certain natural resources, depletion. Costs are deducted over a number of years to reflect an asset’s rate of depreciation or depletion.

In contrast, the U.S. tax code treats extractive industries that produce oil, natural gas, coal, and hard minerals more favorably. Two tax preferences in particular give extractive industries an advantage over other industries:

One preference allows producers of oil, gas, coal, and minerals to “expense” some of the costs associated with exploration and development. Expensing allows companies to fully deduct such costs as they are incurred rather than waiting for those activities to generate income. For extractive companies, the costs that can be expensed include, in some cases, those related to excavating mines, drilling wells, and prospecting for hard minerals. Specifically, current law allows independent oil and gas producers and noncorporate coal and mineral producers to fully expense their costs, and it allows expensing of 70 percent of costs for “integrated” oil and gas producers (companies with substantial retailing or refining activity) and corporate coal and mineral producers, with the companies able to deduct the remaining 30 percent of their costs over 60 months.

A second preference allows extractive industries to use a “percentage depletion allowance.” Through that allowance, certain extractive companies can deduct from their taxable income between 5 percent and 22 percent of the dollar value of material extracted during the year, depending on the type of resource and up to certain limits. For example, oil and gas companies’ eligibility for the percentage depletion allowance is limited to independent producers who operate domestically; for those firms, only the first 1,000 barrels of oil (or, for natural gas, oil-equivalent) per well, per day, qualify, and the allowance is limited to 65 percent of overall taxable income. For each property they own, firms take a deduction for the greater of the percentage depletion allowance or the amount prescribed by the cost depletion system, which allows for recovery of investment costs as income is earned from those investments. Total deductions can be increased by the percentage depletion allowance because it is not limited to the cost of the property, as are the amount of deductions allowed under cost depletion.

This option includes two different approaches to limiting tax preferences for extractive industries. The first approach would replace the expensing of exploration and development costs for oil, gas, coal, and hard minerals with the rules for deducting costs that apply in other industries. That approach would increase revenues by $18 billion over the 2014–2023 period, according to estimates by the staff of the Joint Committee on Taxation (JCT). The second approach would eliminate the percentage depletion allowance. That approach would raise $16 billion over that 10-year period, according to JCT. If the two approaches were combined, revenues would increase by $34 billion over the 2014–2023 period.

The principal argument in favor of this option is that the two tax preferences for extractive industries distort the allocation of society’s resources in several ways. First, for the economy as a whole, the preferences influence the allocation of resources between the extractive industries and other industries in an inefficient manner. Those incentives encourage some investments in drilling and mining that produce a smaller market value of output than the investments would produce elsewhere because, when making investment decisions, companies take into account not only the market value of the output but also the tax advantage that expensing and percentage depletion provide. Second, for the same reason, the preferences also lead to an inefficient allocation of resources within the extractive industries. Third, the preferences encourage producers to extract more resources in a shorter time. In the case of oil, for example, that additional drilling makes the United States less dependent on imported oil in the short run, but it accelerates the depletion of the nation’s store of oil and causes greater reliance on foreign producers in the long run.

An argument against this option is that it treats expenses that might be viewed as similar in different ways. In particular, exploration and development costs for extractive industries can be seen as analogous to research and development costs, which can be expensed by all businesses. Another argument against this option is that encouraging producers to continue exploring and developing domestic energy resources may enhance the ability of U.S. households and businesses to accommodate disruptions in the supply of energy from other countries.